1. Technical Field
The present disclosure relates to acoustic devices and, particularly, to a thermoacoustic device.
2. Description of Related Art
Acoustic devices generally include a signal device and a sound wave generator electrically connected to the signal device. The signal device inputs signals to the sound wave generator, such as loudspeakers. A loudspeaker is an electro-acoustic transducer that converts electrical signals into sound.
There are different types of loudspeakers that can be categorized according to their working principle, such as electro-dynamic loudspeakers, electromagnetic loudspeakers, electrostatic loudspeakers, and piezoelectric loudspeakers. These various types of loudspeakers use mechanical vibration to produce sound waves. In other words they all achieve “electro-mechanical-acoustic” conversion. Among the various types, the electro-dynamic loudspeakers are the most widely used.
A thermophone based on the thermoacoustic effect was made by H. D. Arnold and I. B. Crandall (H. D. Arnold and I. B. Crandall, “The thermophone as a precision source of sound,” Phys. Rev. 10, pp 22-38 (1917)). However, the thermophone adopting the platinum strip produces weak sounds because the heat capacity per unit area of the platinum strip is too high.
What is needed, therefore, is to provide a thermoacoustic device having good sound effect and high efficiency.